1. Field of the Invention
The present invention relates to an emulsion/resin composition that is sprayed onto a working surface with a spray gun that cuts the resin into strands having varying lengths.
2. Description of Related Art
There has existed building materials which can be constructed by spraying a working surface with an emulsion. The emulsion is typically a mixture of asphalt, clay and water. After the emulsion is sprayed onto the surface, the water evaporates and the asphalt hardens into a solid structure. Such a process is typically used to cover the roof of a building.
To improve the strength of the asphalt structure, a resin is typically sprayed with the emulsion. The resin adds stiffness to the structure and prevents the asphalt from easily cracking or tearing. The most commonly used resin is fiber glass which is cut into strands and blown onto the working surface with the asphalt emulsion.
U.S. Pat. No. 3,155,320 issued to Jones; U.S. Pat. No. 3,947,962 issued to Smith et al; U.S. Pat. No. 3,111,272 issued to Underdown et al and U.S. Pat. Nos. 3,249,307 and 3,504,861 issued to Peeps et al, disclose spray guns used to spray emulsion and glass fibers onto a surface. The spray guns have a cutting wheel that is typically rotated by a friction wheel which feeds a single fiber glass thread between the two wheels. The cutting wheel has a number of blades that can rotate and cut the thread into individual strands. The strands are then blown by the spray gun onto the working surface. The blades of the cutting wheel are spaced apart an equal distance, so that the individual strands all have the same length. The guns typically have a pair of nozzles that are attached to a pressurized source of emulsion. The nozzles are oriented to spray the emulsion into the path of the strands, so that the emulsion and strands are mixed together on the surface.
As disclosed in U.S. Pat. No. 3,829,016 issued to Scharfenberger, the typical length of a resin strand is between 0.5-1.5 inches. Although using glass strands of such size is an effective way of spraying and mixing the resin with the emulsion, it has been found that the resulting harden composition is relatively weak.
U.S. Pat. No. 3,096,225 issued to Carr et al and U.S. Pat. No. 3,212,691 issued to Lockshaw disclose a method of constructing an emulsion/resin composition by blowing a continuous strand(s) of fiber glass onto the working surface. Although a continuous strand of fiber increases the strength of the resulting asphalt composition, it is difficult to make the single strand lie flat on the working surface. As discussed in the Carr patent, after the emulsion and glass resin are sprayed onto the working surface, the emulsion/resin material must be flattened to form a smooth uniform composition. Such a process increases the time and cost of constructing the structure. It would therefore be desirable to have a system that produces a strong emulsion/resin composition that can be efficiently sprayed onto a working surface.